LED Watch Electronics Kit

Includes all components required to build the LED Watch:

• LED Watch PCB
• STC15W408AS Microcontroller
• DS1302 Timekeeping Chip
• 32.768 kHz Crystal Oscillator
• Monolithic capacitor (104) ×1
• Ceramic capacitors (22 pF) ×2
• 10 kΩ resistors ×3
• Tactile push buttons ×2
• 4-digit, 7-segment LED display
• CR2032 battery holder
• Clear acrylic watch case
• Adjustable Velcro wrist strap
• Screws and nuts for case assembly

Refer to the image gallery for photographs of each component.

This kit, along with our detailed instruction manual has a wide range of learning benefits for curious kids, or indeed anyone interested in learning about electronics. Along with photographic instructions, the manual includes the circuit diagram and a technical description that teaches how all components work together to produce an accurate timekeeping device. Read on to learn more...

Introduction to electronics and soldering: Learn how to solder resistors, chips, oscillators, and displays to a PCB. Gain steady hands, patience, and precision—skills used in every electronics and craft projects.

Circuit design basics: Understand how printed circuit boards connect components to form a functioning digital system.

Timekeeping technology: Explore how oscillators and microcontrollers combine to keep time with remarkable accuracy (±0.5 seconds per hour).

Microcontrollers in action: See how a simple microcontroller manages inputs, display control, and accurate time tracking. This knowledge is the foundation of robotics, embedded systems, and IoT devices.

LED display operation: Learn how 7-segment LED digits are multiplexed by a microcontroller to display numbers without using dozens of pins.

Logical thinking & problem-solving: Debugging and troubleshooting teach resilience, attention to detail, and real-world engineering skills.

Wearable tech insight: Discover the technology behind digital watches and how modern devices are engineered to balance size, power, and function.

Confidence & creativity: Finish with a working LED wristwatch you built yourself. Wear it with pride, show it off, or even customise the strap or case for a personal touch.

STEM career inspiration: Great for students interested in engineering, programming, robotics, or product design. Early exposure to microcontrollers and circuit design inspires interest in technology fields. Almost all scientists were inspired from experiences with STEM toys such as this kit at an early age!

Family-friendly learning: An excellent weekend STEM project for parent-child bonding. Build something together that’s not only fun but also educational.

Q: Is the battery included?
A: A CR2032 battery is included in the kit for most regions. However, the battery may need to removed before shipping to meet safety regulations in some countries/regions. In these cases, you can buy your own battery for around $1-$2 (readily available in local stores).

Q: Does the watch really work after assembly?
A: Yes! Once complete, you’ll have a fully functional LED digital wristwatch with accurate timekeeping.

Q: Does it need coding or programming?
A: No coding required. The microcontroller is pre-programmed—you just build the hardware.

Q: Can it be used in classrooms or workshops?
A: Absolutely. This kit is a great choice for STEM education, homeschool projects, and engineering clubs. It provides hands-on electronics experience with a rewarding, wearable result.

Q: How long does the battery last?
A: The watch includes an auto-power off feature to conserve battery. After 5 seconds, the display turns off. With this feature, a good quality battery will last a long time, from several months to more than a year, depending on how often you turn on the display.

Q: Is the watch waterproof?
A: No. The acrylic case is protective but not waterproof, so avoid contact with water.

Dimensions (approx., when completed):

• Watch-face diameter: 5.5 cm
• Height: 1.7 cm
• Strap length: 27 cm
• Weight: 38 g (including battery)

PCB Type: All through-hole components.

LED display block height: 1.0 cm

Displayed digit height: 0.7 cm

Accuracy: ±0.5 seconds per hour

Power Supply: 1 x CR2032 Lithium battery

Anyone can build this LED Watch Electronics kit following our detailed step-by-step instruction manual which can be downloaded from the link below. The password to open the manual was sent to the same email that you placed your order from. Can't find it? Just Contact Us!

Download: LED Watch Electronics Kit Instruction Manual

Skill Level: Beginners
Age Rating: 12+ (adult supervision required for under 16's)
Assembly Time: Typically 1-3 hours

Tools required for this kit

• Soldering iron
• Solder wire

We sell these items as a bundle for just €25.95 (or currency equivalent) which saves 10 percent! Just click the link below to select your countries plug type and add to your order.

SOLDERING IRON & WIRE BUNDLE

Of course, you only need to buy the tools once; you'll use them again and again for your future electronics projects!

Our blogs & videos related to electronics kits:

Ultimate Guide to Electronics Kits

STEM Electronics as a Hobby

Youtube video: Tools, tips and tricks for soldering electronics kits

Other useful links:

Tutorial about 7-segment LED digital displays